Expanding bar



May 17, 1932. B. w. SNODGRASS EXPANDING; BAR

Filed July 11, 1927 A w 5& fllllmwl. .111. Ill ml MN QN QM s MN mm w NQMaw m $1 w .m\

Patented May 17, 1932 UNITED STATES EXPANDING BAR Application filed July11,

This invention relates to expanding bars to be used in mining, and moreparticularly in breaking coal, rock or other material and loosening thesameso that it may be brought down in the working space of a coal minewithout danger to the operator or others working in the mine and withoutinjury to the roof of the mine. The old method of using blasting powderwas extremely hazardous and by its use a great percentage of broken coalor slack resulted. The danger of gas or coal explosion, so oftenattendant upon the use of blasting powder, will be, by the use of thisinvention, entirely eliminated.

One of the objects of this invention is to provide an expandin barwherein the expansive force of the wec ge is exerted at several distinctpoints simultaneously.

Another object of the device is to provide an expanding bar in which theinner wedge bar is retracted in order to expand the outer wedge orsleeve member or members.

A still further object is to provide a novel wedge member for saidexpanding bar. 7

Other objects, advantages and capabilities are comprehended by theinvention as will later appear and are inherently possessed thereby.

Referring now to the accompanying draw- 39 ings:

Fig. l is a plan View of the novel form of wedge bar.

Fig. 2 is a plan view of one of the outer wedge members or sleeve.

Fig. 3 is a view in elevation of one of the outer wedge or sleevemembers adapted to be used with the form of wedge bar shown in Fig. 1.

Fig. 4 is an end view of the formof expand- 40 ing gar looking in thedirection of the arrows Fig. 5 is a transverse sectional view taken in aplane represented byline HH of Fig. 1.

Fig. 6 is a transverse sectional view taken in a plane represented byline J J of Fig. 10.

Fig. 7 is a similar transverse sectional View, as Fig. 6, showing thebar in expanded relation.

Figs. 8 and 9 are end views of a segment of the outer wedge member orsleeve shown in 1927. Serial No. 204,965.

Fig.2, Fig. 9 being taken at the rectangular. end of the outer wedgemember.

Fig. 10 is a plan view of the novel form of expanding bar, connectedwith a means for re- I stantially rectangular, each of thefour sides 7being provided with a tongue or rib 9 that runs along substantially theentire length of each" of the wedges.

Means suitably adapted to retract the wedge bar is shown in Figs. 1 and10. This means consists of a screw threaded member 13 suitably attachedto the end of the wedge bar. A sleeve member 14' encompasses'the shaftand abuts against the hubl5 of a gear 7 wheel 16. The hub 15 isinternally screw threaded so as to mesh with the screw threads on themember 13. Thus by the rotation of the gear wheel (which may be drivenby any suitable means), the member 13 will be retracted. This member 13in turn will retract the wedge bar and its sections 17,18 and 19, andthe retraction of the wedge bar. willv expand the outer wedge member orsleeve composed of four segments 20, 21, 22 and 23, these segmentsmerging into the substantially triangular sections 24, as shown in Fig.9.

When the expanding bar is in its contracted position, these sectionsform airectangle and the four segments form aicircle, Each of the foursides of the wedge bar is provided with a tongue or rib 9 that isadapted to register or interlockwth: the respective grooves 11 of theouter wedge or sleeve members. The cross-section of the wedges decreasesrearwardly, so that atthe point of connection of the individual wedges,their cross-section will be smallest, while at the forward end of theindividual wedges, the cross section will be greatest. 10- dis closesthe novel form of expanding bar in assembled and contracted relation,and combined with the gear mechanism for retracting the inner wedge bar.I

An important feature of the invention is that when the wedge bar is inits most retracted position, the inner or forward end of the outersleeve member or wedge member is at all times positively supported alongits entire inner face by the inner wedge bar. This is of extremeimportance as the inner or forward end has to do the greatest amount ofwork in breaking the coal or other material that is being operated upon.With its outer member not supported inthis manner, it would be rathereasily crushed or bent out of shape, and thus necessarily the innerwedge bar could not properly position itself within the outer wedgemembers or sleeve. Even though the outer sleeve members are not at alltimes supported along their entire face,

this is not disastrous as coal, rock and the like, not being resilient,the unsupported parts are relieved of pressure by the working orspreading portions.

It is to be understood that the means and;

, parts and features without departing from the spirit thereof.

I claim:

1. In an expanding bar, an inner wedge bar having its opposite'sidesbeveled, each of said sides being provided with a rib, and an outerwedge member composed of four segments, each of said segments providedw1th a groove adapted to engage a rib on the sides of the inner wedgebar, said outer segments forminga circular shaped bar when the innerwedge bar is in its contracted position. 2. In an expanding bar, an mnerwedge bar having its opposite sides beveled to form 6 in cross section asquare when said cross section is taken at any point along the bar, thesides of said bar being provided with a rib,

and an outer wedge member composed of four segments, each of saidsegments provided w1th a groove adapted to engage a rib on the sldes ofthe mner wedge bar,sa1d outer V Wedge forming an exterior circularshell, the

I tracted position.

inner faces of which engage and are in continuous surface contact withthe sides of the inner wedge bar when said bar is in its con '3. In anexpanding bar, an inner member having a plurality of surfaces bevelledto, form a wedge bar, each of said surfaces bemg provided with arib, andan outer wedge member comprising a plurality of segments,.

each of said segments provided with a groove adapted to engage the ribsof said inner member, each of said segments having its edges incontacting engagement with adjacent segments to form a circular shapedbar when the inner wedge bar is in its contracted position. r

In witness whereof, I hereunto subscribe my name to this specification.

BENJAMIN WALTER SNODGRASS.

